Exactly matching the background of a selected NSMenuItem

Question

I am creating a custom view for an NSMenuItem. In order to draw the background when selected, I adapted a couple of lines from the CustomMenus sample. The CustomMenus sample has:

    [[NSColor alternateSelectedControlColor] set];
    NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);

.. and I am using the selectedMenuItemColor because the alternateSelectedControlColor was a solid color and it did not look very good:

    [[NSColor selectedMenuItemColor] set];
    NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);

Using selectedMenuItemColor is better, but it's still not exactly the same as a real selected NSMenuItem.

Here is a screenshot showing the real selected NSMenuItem background on the left and the selectedMenuItemColor on the right in the "Blue" appearance:

You can see that there is an additional translucent white gradient overlay on the real selected NSMenuItem background.

How do I replicate the real selected NSMenuItem background?

EDIT: This is for Mac OS 10.9.5.

EDIT2: Here is a side-by-side comparison in the "Graphite" appearance:

Answer 1

Through trial and error I came up with the following code that draws a background almost indistinguishable from the real selected NSMenuItem background in both "Blue" and "Graphite" appearances:

    [[NSColor selectedMenuItemColor] set];
    NSRectFillUsingOperation(dirtyRect, NSCompositeSourceOver);

    if (dirtyRect.size.height > 1) {
        const NSControlTint currentControlTint = [NSColor currentControlTint];

        const CGFloat startingOpacity = (NSBlueControlTint == currentControlTint ? (CGFloat)0.16 : (CGFloat)0.09);
        NSGradient *grad = [[NSGradient alloc] initWithStartingColor:[NSColor colorWithWhite:(CGFloat)1.0 alpha:startingOpacity] endingColor:[NSColor colorWithWhite:(CGFloat)1.0 alpha:(CGFloat)0.0]];

        const CGFloat heightMinus1 = (CGFloat)(dirtyRect.size.height - 1);
        [grad drawFromPoint:NSMakePoint(dirtyRect.origin.x, dirtyRect.origin.y + heightMinus1) toPoint:NSMakePoint(dirtyRect.origin.x, dirtyRect.origin.y + 1) options:0u];

        if (NSBlueControlTint == currentControlTint) {
            [[NSColor colorWithWhite:(CGFloat)1.0 alpha:(CGFloat)0.1] set];
            NSRectFillUsingOperation(NSMakeRect(dirtyRect.origin.x, dirtyRect.origin.y + heightMinus1, dirtyRect.size.width, (CGFloat)1.0), NSCompositeSourceOver);
        }
    }

Here are side-by-side comparisons:

The left halves (80px) of the two images show the real selected NSMenuItem background and the right halves of the two images are the result of the code.